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PubMed1978

Radiologic-pathologic correlations of small lung nodules with special reference to peribronchiolar nodules.

A radiologic and pathologic correlation has been made of small lung nodules. At necropsy 100 excised lungs were fixed and slices from them radiographed. The radiographs were used to select individual nodules for histologic study. Nodules in bronchopneumonia, acinonodose tuberculosis, chronic bronchiolitis, and simple pneumoconiosis due to ferric dust were shown to be located around inflamed terminal or respiratory bronchioles. Intraacinar infiltration was usually diffuse, but when nodules were seen, they occurred in peripheral airspaces with no relation to bronchioles. Hematogenous metastases showed distinctly marginated nodules, some truly intraacinar. Although each type of nodule can appear as an "acinar" or "subacinar" image on chest radiographs, this radiologic-pathologic study shows that they differ significantly in their relation to the airway structures.

Adult↗

PubMed1983

Experimental lung nodule model: CT numbers, nodule size, and actual calcium content.

An experimental pulmonary nodule model was developed to study the effect of nodule size, nodule environment, and calcium content on the attenuation values in two computed tomography (CT) scanners. The experimental results show that (a) calcium is the moiety most responsible for the CT number, (b) small nodules may have falsely low CT numbers, (c) CT numbers vary from scanner to scanner when scanning the same nodule, and (d) higher CT numbers are obtained when experimental nodules are scanned in air rather than water.

Calcinosis↗

PubMed1995

The nodule-specific VfENOD-GRP3 gene encoding a glycine-rich early nodulin is located on chromosome I of Vicia faba L. and is predominantly expressed in the interzone II-III of root nodules.

A nodule-specific cDNA was isolated from a Vicia faba L. nodule cDNA library. Since time course experiments revealed an early expression of this transcript in the nodule, this cDNA coded for an early nodulin and was designated VfENOD-GRP3. Based on tissue print hybridizations, we found a predominant expression of VfENOD-GRP3 transcripts in the interzone II-III region of broad bean root nodules. The encoded early nodulin ENOD-GRP3 was characterized by an N-terminal signal peptide and a C-terminal domain displaying a glycine content of 31%. Sequence analysis of a genomic VfENOD-GRP3 clone revealed that the signal peptide and the glycine-rich domain were specified by two separate exons. Primer extension experiments identified two adjacent transcription start sites for VfENOD-GRP3 transcripts. The common nodulin sequences 'AAAGAT' and 'CTCTT' were present five and three times on both DNA strands of the putative VfENOD-GRP3 promoter, respectively. Additionally, three sequence motifs resembling organ-specific elements of the soybean lbc3 gene promoter and a sequence similar to the binding site 1 for the nodule trans-acting factor Nat2 were identified. From Southern blot data and from sequence analysis of genomic PCR fragments, the presence of a VfENOD-GRP3 gene family was inferred. By PCR experiments using sequence-specific primers and DNA of microisolated chromosomes as a template, this family was located on the long arm of chromosome I.

Amino Acid Sequence↗

PubMed2000

The promoter of the Vicia faba L. gene VfEnod12 encoding an early nodulin is active in cortical cells and nodule primordia of transgenic hairy roots of Vicia hirsuta as well as in the prefixing zone II of mature transgenic V. hirsuta root nodules.

A full-length cDNA encoding the Vicia faba L. early nodulin VfEnod12 was isolated. The deduced protein sequence specified a 90 amino acid protein with a MW of 10206 and contained a putative signal peptide sequence followed by PPX(3) repeats characteristic of Enod12 proteins. The VfEnod12 gene was found to be expressed specifically in root nodules as early as 3 days post inoculation with Rhizobium leguminosarum bv. viciae. In mature nodules, VfEnod12 transcripts were confined to the prefixing zone II. A 3.3 kb genomic fragment carrying the complete VfEnod12 coding region was isolated. No intervening sequences were identified in the coding region. A promoter fragment carrying the -692/-41 region mediated reporter gene expression in root cortical cells, nodule primordia and the prefixing zone II of transgenic Vicia hirsuta root nodules. This fragment contained a putative binding site for the transcription factor ENBP1. In contrast to the highly conserved terminal AATAA motif of the ENBP1 binding site of known Enod12 promoters, the VfEnod12 promoter was characterized by an altered terminal AATAT sequence. This alteration did not interfere with VfEnod12 promoter activity in transgenic roots and nodules of V. hirsuta.

Journal Article↗

PubMed1985

Conservation of nodulation genes between Rhizobium meliloti and a slow-growing Rhizobium strain that nodulates a nonlegume host.

Parasponia, a woody member of the elm family, is the only nonlegume genus whose members are known to form an effective nitrogen-fixing symbiosis with a Rhizobium species. The bacterial strain RP501 is a slow-growing strain of Rhizobium isolated from Parasponia nodules. Strain RP501 also nodulates the legumes siratro (Macroptilium atropurpureum) and cowpea (Vigna unguiculata). Using a cosmid clone bank of RP501 DNA, we isolated a 13.4-kilobase (kb) EcoRI fragment that complemented insertion and point mutations in three contiguous nodulation genes (nodABC) of Rhizobium meliloti, the endosymbiont of alfalfa (Medicago sativa). The complemented R. meliloti nod mutants induced effective nitrogen-fixing nodules on alfalfa seedlings but not on siratro, cowpeas, or Parasponia. The cloned RP501 nodulation locus hybridized to DNA fragments carrying the R. meliloti nodABC genes. A 3-kb cluster of Tn5 insertion mutations on the RP501 13.4-kb EcoRI fragment prevented complementation of R. meliloti nodABC mutations.

Journal Article↗

PubMed2003

Local and systemic effects of phosphorus and nitrogen on nodulation and nodule function in Alnus incana.

Phosphorus (P) and nitrogen (N) effects on nodulation, nitrogenase activity and plant growth were studied in the root-hair-infected actinorhizal plant Alnus incana (L.) Moench. A split-root experiment, as well as a short-term experiment with entire root systems and a broader range of P concentrations, showed that P effects were specific on nodulation and not a general stimulation via a plant growth effect. These results indicate that nodule initiation and nodule growth have a high P demand. The split-root assay, comprising seven combinations of two N and two P levels, showed that P could counteract systemic N inhibition of nodulation, but did not counteract N inhibition of nitrogenase activity.

Alnus↗

PubMed2005

GuaB activity is required in Rhizobium tropici during the early stages of nodulation of determinate nodules but is dispensable for the Sinorhizobium meliloti-alfalfa symbiotic interaction.

The guaB mutant strain Rhizobium tropici CIAT8999-10T is defective in symbiosis with common bean, forming nodules that lack rhizobial content. In order to investigate the timing of the guaB requirement during the nodule formation on the host common bean by the strain CIAT899-10.T, we constructed gene fusions in which the guaB gene is expressed under the control of the symbiotic promoters nodA, bacA, and nifH. Our data indicated that the guaB is required from the early stages of nodulation because full recovery of the wild-type phenotype was accomplished by the nodA-guaB fusion. In addition, we have constructed a guaB mutant derived from Sinorhizobium meliloti 1021, and shown that, unlike R. tropici, the guaB S. meliloti mutant is auxotrophic for guanine and induces wild-type nodules on alfalfa and Medicago truncatula. The guaB R. tropici mutant also is defective in its symbiosis with Macroptilium atropurpureum and Vigna unguiculata but normal with Leucaena leucocephala. These results show that the requirement of the rhizobial guaB for symbiosis is found to be associated with host plants that form determinate type of nodules.

Artificial Gene Fusion↗

PubMedDate not supplied

ENOD8, a novel early nodule-specific gene, is expressed in empty alfalfa nodules.

The alfalfa ENOD8 nodule-specific gene is expressed in empty nodules elicited by exopolysaccharide-deficient Rhizobium meliloti, and it is expressed early in nodule development. An ENOD8 cDNA was sequenced and found to encode a novel product. Its deduced polypeptide sequence was found to be similar to the nonproline-rich domains of the putative polypeptides encoded by a class of anther-specific genes from Arabidopsis thaliana and Brassica napus. The role of the ENOD8 gene product is predicted to be in nodule organogenesis. ENOD8 is expressed in a developmental pathway triggered as a result of Rhizobium nodulation signal transduction.

Amino Acid Sequence↗

PubMed1999

Aberrant nodulation response of Vigna umbellata to a Bradyrhizobium japonicum NodZ mutant and nodulation signals.

The (Brady)rhizobium nodulation gene products synthesize lipo-chitin oligosaccharide (LCO) signal molecules that induce nodule primordia on legume roots. In spot inoculation assays with roots of Vigna umbellata, Bradyrhizobium elkanii LCO and chemically synthesized LCO induced aberrant nodule structures, similar to the activity of these LCOs on Glycine soja (soybean). LCOs containing a pentameric chitin backbone and a reducing-end 2-O-methyl fucosyl moiety were active on V. umbellata. In contrast, the synthetic LCO-IV(C16:0), which has previously been shown to be active on G. soja, was inactive on V. umbellata. A B. japonicum NodZ mutant, which produces LCO without 2-O-methyl fucose at the reducing end, was able to induce nodule structures on both plants. Surprisingly, the individual, purified, LCO molecules produced by this mutant were incapable of inducing nodule formation on V. umbellata roots. However, when applied in combination, the LCOs produced by the NodZ mutant acted cooperatively to produce nodulelike structures on V. umbellata roots.

Bacterial Proteins↗

PubMed2003

Comparison of nodule induction in legume and actinorhizal symbioses: the induction of actinorhizal nodules does not involve ENOD40.

Two types of root nodule symbioses are known for higher plants, legume and actinorhizal symbioses. In legume symbioses, bacterial signal factors induce the expression of ENOD40 genes. We isolated an ENOD40 promoter from an actinorhizal plant, Casuarina glauca, and compared its expression pattern in a legume (Lotus japonicus) and an actinorhizal plant (Allocasuarina verticillata) with that of an ENOD40 promoter from the legume soybean (GmENOD40-2). In the actinorhizal Allocasuarina sp., CgENOD40-GUS and GmENOD40-2-GUS showed similar expression patterns in both vegetative and symbiotic development, and neither promoter was active during nodule induction. The nonsymbiotic expression pattern of CgENOD40-GUS in the legume genus Lotus resembled the nonsymbiotic expression patterns of legume ENOD40 genes; however, in contrast to GmENOD40-2-GUS, CgENOD40-GUS was not active during nodule induction. The fact that only legume, not actinorhizal, ENOD40 genes are induced during legume nodule induction can be linked to the phloem unloading mechanisms established in the zones of nodule induction in the roots of both types of host plants.

Base Sequence↗

PubMedDate not supplied

The autonomous nodule of the thyroid: correlation of patient age, nodule size and functional status.

In light of new techniques for measuring circulating thyroid hormones and for studying the thyroid gland, we present our experience with 35 patients with solitary autonomous nodules of the thyroid to define more precisely the clinical course of patients with this disorder. The patients ranged in age from 19 to 80 years and 31 of the 35 were female. Younger patients were generally euthyroid and sought attention because of a thyroid mass; virtually all older patients were hyperthyroid. Eighteen had obvious clinical features of hyperthyroidism and 5 over age 70 had apathetic hyperthyroidism; all 5 of the elderly and 13 of the 18 under age 70 had elevated thyroxine (T4) and triiodothyronine (T3) levels. Isolated elevation of T3 and elevated basal metabolic rate were observed in 5 previously untreated clinically hyperthyroid young patients. In each of these, thyroid uptake of 131-I was not suppressible with exogenous T3 and BMR was elevated in those tested. Two elderly patients, who had previously been treated for conventional hyperthyroidism with radioactive iodine, had T3 toxicosis when hypoethyroidism recurred. There was a strong positive correlation between the age of the patient, the size of the nodule and the thyroid functional state. The mean area of the nodules projected on 131-I rectilinear scan for euthyroid patients was 5.1 cm2. The mean area of the nodules in hyperthryoid subjects was significantly higher, 13.4 cm-2 in patients with T3 toxicosis and 19.3 cm-2 in subjects with conventional hyperthyroidism. Progression from a euthyroid state to hyperthyroidism was observed four patients. One of these became thyrotoxic within days after an injection of iodinated contrast medium. Spontaneous resolution of nodules occurred in two patients.

Adenoma↗

PubMed2006

Comparative analysis of expression profiling of early-stage carcinogenesis using nodule-in-nodule-type hepatocellular carcinoma.

BACKGROUND: Nodule-in-nodule-type hepatocellular carcinoma (NIN-HCC) is a useful model to illustrate the multi-step nature of hepatocarcinogenesis. To identify large-scale molecular change in early hepatocarcinogenesis, the expression profile of NIN-HCC was compared with those from three sets of individual high-grade dysplastic nodules (HGDN) and grade 1 hepatocellular carcinomas. METHODS: We compared expression profiles of inner grade 1 hepatocellular carcinoma nodules and peripheral HGDN in one case of NIN-HCC using spotted-oligonucleotide DNA microarray. The relevant outlier genes assumed to associate with early carcinogenesis in hepatocellular carcinoma were identified by comparative analysis of NIN-HCC and individual cases of HGDN and grade 1 hepatocellular carcinoma, respectively. RESULTS: From this analysis we extracted a total of 40 genes, consisting of 28 up-regulated genes and 12 downregulated genes, and more than a two-fold change in grade 1 hepatocellular carcinoma compared with HGDN. CONCLUSION: We assessed the expression profiles of pre-neoplastic lesions and grade 1 hepatocellular carcinoma using oligonucleotide microarray analysis and found high stringent outlier genes that are presumably directly involved in the transition from dysplastic nodule to the early stage of hepatocellular carcinoma by utilizing NIN-HCC.

Carcinoma, Hepatocellular↗

PubMed1994

A Peanut Nodule Lectin in Infected Cells and in Vacuoles and the Extracellular Matrix of Nodule Parenchyma.

Root nodules on peanut (Arachis hypogaea L.) accumulate a galactose/lactose-binding lectin that is similar, but not identical, to the major seed lectin in peanut. The function of the peanut nodule lectin (PNL) is not known. In the current study, we have investigated the location of lectin in the nodule using immunogold labeling and enzyme-linked immunosorbant assays (ELISA). Lectin was most abundant in the nodule parenchyma, where it accumulated in vacuoles, suggesting a possible role as a vegetative storage protein. Lectin was also detected in the extracellular matrix in the nodule parenchyma, a location that corresponds to the tissue layer forming a barrier to oxygen diffusion. The potential for interactions between PNL and other cell wall components, including a previously described high-molecular weight glycoprotein that co-localizes with PNL, is discussed. Within infected cells, lectin was not detectable by immunogold labeling within the cytoplasm, but light labeling was suggestive of lectin localization within the symbiosome lumen. Analysis of fractionated symbiosomes by the more sensitive ELISA technique confirmed that lectin was present within the symbiosome, but was not bound to bacteroids. Our results indicate that PNL probably plays several roles in this nitrogen-fixing symbiosis.

Journal Article↗

PubMed1990

Two plasmids other than the nodulation plasmid are necessary for formation of nitrogen-fixing nodules by Rhizobium leguminosarum.

A system which allows direct selection for curing of plasmids in Gram-negative bacteria was used to generate derivatives of Rhizobium leguminosarum VF39 cured of each of six plasmids present in this strain. Phenotypes could be correlated with the absence of five of the six plasmids. The smallest plasmid, pRleVF39a, carries genes for the production of a melanin-like pigment as has been previously reported. Plasmid pRleVF39d carries nodulation and nitrogen fixation genes. Curing of the plasmids pRleVF39c and pRleVF39e gave rise to strains which formed Fix- nodules on peas, lentils, and faba beans. The nodules formed by the strains cured of pRleVF39c contained few, if any, bacteria. Analysis of washed cells by SDS-PAGE showed that this strain is defective in lipopolysaccharide (LPS) production; the defect could be complemented by introducing plasmids from several other R. leguminosarum strains, and by the R. leguminosarum biovar phaseoli LPS gene clones pCos126 and pDel27. The nodules formed by the strain cured of pRleVF39e had a reduced symbiotic zone, an enlarged senescence zone, and an abundance of starch granules. This strain grew at a much slower rate than the wild type, was unable to grow on minimal medium, and no longer produced melanin. These defects could be complemented by at least one other Rhizobium plasmid, pRle336e, a plasmid of strain 336 which is distinct from the nodulation plasmid (pRle336c) and the plasmid (pRle336d) which could complement the LPS defect associated with the loss of pRleVF39c. This demonstrates that genes necessary for symbiosis can be carried on at least three different plasmids in R. leguminosarum.

DNA Transposable Elements↗

PubMed1992

Rhizobium leguminosarum has two glucosamine synthases, GlmS and NodM, required for nodulation and development of nitrogen-fixing nodules.

The Rhizobium leguminosarum nodM gene product shows strong homology to the Escherichia coli glmS gene product that catalyses the formation of glucosamine 6-P from fructose 6-P and glutamine. DNA hybridization with nodM indicated that, in addition to nodM on the symbiotic plasmid, another homologous gene was present elsewhere in the R. leguminosarum genome. A glucosamine-requiring mutant was isolated and its auxotrophy could be corrected by two different genetic loci. It could grow without glucosamine when the nodM gene on the symbiotic plasmid was induced or if the cloned nodM gene was expressed from a vector promoter. Alternatively, it could be complemented by a second fragment of R. leguminosarum DNA that carries a region homologous to E. coli glmS. Biochemical assays of glucosamine 6-P formation confirmed that the two R. leguminosarum genes nodM and glmS have interchangeable functions. No nodulation of peas or vetch was observed with a double nodM glmS mutant, and this block occurred at a very early stage since no root-hair deformation or infection threads were seen. Nodulation and root-hair deformation did occur with either the nodM or the glmS mutant, showing that the gene products of either of these genes can be involved in the formation of the lipo-oligosaccharide nodulation signal. However, the glmS mutant formed nodules that had greatly reduced nitrogen fixation. Constitutive expression of nodM restored nitrogen fixation to the glmS mutant. Therefore the reduced nitrogen fixation probably occurs because glmS is absent and nodM is not normally expressed in nodules and, in the absence of glucosamine precursors, normal bacteroid maturation is blocked.

Cloning, Molecular↗

PubMed1993

Ethylene Production by Root Nodules and Effect of Ethylene on Nodulation in Glycine max.

Nodulated soybean roots produced more ethylene and contained more 1-aminocyclopropane-1-carboxylic acid than uninoculated roots. Nodules produced more ethylene and contained more 1-aminocyclopropane-1-carboxylic acid per gram of material than roots. Almost all of the ethylene produced by the nodules was produced by the plant fractions of the nodules. Ethylene, at physiological concentrations, did not inhibit nodulation in soybeans.

Journal Article↗

PubMed1986

Molecular cloning and expression of Rhizobium fredii USDA 193 nodulation genes: extension of host range for nodulation.

DNA hybridization with the cloned nodulation region of Rhizobium meliloti as a probe revealed DNA homology with four HindIII fragments, 12.5, 6.8, 5.2, and 0.3 kilobases (kb) in size, of the symbiotic plasmid pRjaUSDA193. Both hybridization and complementation studies suggest that the common nodulation genes nodABC and nodD of R. fredii USDA 193 are present on the 5.2-kb HindIII and 2.8-kb EcoRI fragments, respectively, of the Sym plasmid. Both fragments together could confer nodulation ability on soybeans when present in Sym plasmid-cured (Sym-) and wild-type (Sym+) Rhizobium strains or in a Ti plasmid-cured Agrobacterium tumefaciens strain. Furthermore, the 2.8-kb EcoRI fragment alone was able to form nodulelike structures on Glycine max L. cv. "Peking" (soybean). Microscopic examination of these nodules revealed bacterial invasion of the cells, probably via root hair penetration. Bacterial strains harboring plasmids carrying the 5.2- and 2.8-kb nod fragments elicited root-hair-curling responses on infection. These data suggest that the genes responsible for host range determination and some of the early events of nodulation may be coded for by the 5.2-kb HindIII and 2.8-kb EcoRI fragments.

Cloning, Molecular↗

PubMed2004

'Nodule-in-nodule' appearance in hepatocellular carcinoma: its significance as a morphologic marker of dedifferentiation.

Small hepatocellular carcinoma (HCC) of the early stage can be divided into 2 types: small nodular HCC with distinct margins and small HCC with indistinct margins. The latter consists uniformly of well-differentiated cancerous tissue with a replacing growth at the boundary, and many portal tracts are retained in the tumor. When such tumors reach around 1.5-2.0 cm in diameter, moderately or poorly differentiated cancer tissues develop within the well-differentiated cancer tissue, and well-differentiated cancerous tissues are replaced by less differentiated cancerous tissues. Such a dedifferentiation seems to be closely related to tumor proliferation. When less differentiated cancerous tissues within the well-differentiated cancer nodules proliferate in an expansive fashion, a 'nodule-in-nodule' appearance is frequently seen. Thus, a 'nodule-in-nodule' appearance in early-stage HCC could be interpreted as a morphologic marker of dedifferentiation of early HCC.

Carcinoma, Hepatocellular↗